In a remarkable archaeological discovery, declassified photos from United States spy satellites launched during the Cold War have unveiled the existence of hundreds of previously unknown Roman-era forts in what is now Iraq and Syria. These long-lost structures challenge a popular hypothesis regarding their purpose along the ancient Roman Empire's eastern border, as researchers report in the journal Antiquity.

Many of these forts, unfortunately, may have been destroyed or damaged over recent decades due to agricultural expansion, urban development, and conflict. However, the discovery of their presence sheds new light on their potential function. Contrary to the long-standing theory that these forts were built to keep enemies out, the satellite images indicate that they likely served as safe passages for caravans and travelers along heavily trafficked nonmilitary routes. The researchers propose that these forts were more like outposts and havens, rather than hostile barriers.

The high-resolution images analyzed in this groundbreaking study were captured by two US military satellite programs: the Corona Project (1960 to 1972) and Hexagon (1971 to 1986). Declassified in 1995 and 2011 respectively, these images offer an invaluable glimpse into landscapes that have undergone significant disruptions since.

Lead study author Jesse Casana, an archaeologist and professor at Dartmouth College in New Hampshire, emphasized the importance of satellite imagery in such archaeological investigations. Casana stated that these images allow researchers to observe features that have been obscured or are no longer present due to the destructive impacts of agriculture and urbanization.

The northern part of the Fertile Crescent in the Middle East, stretching from the eastern Mediterranean coast to western Iran, is particularly fertile ground for satellite surveys due to the region's archaeological significance and the high visibility of the land in photographs.

The research team meticulously scoured the images for the characteristic square shape and the average length of 164 to 262 feet (50 to 80 meters) that define Roman forts. They began by comparing the images to reference maps from an aerial survey conducted in the 1920s and 1930s by French archaeologist Father Antoine Poidebard. While Poidebard's survey initially reported 116 Roman forts along the eastern boundary of the Roman Empire, the satellite images revealed a much larger cluster of 396 fortified structures spreading from east to west.

A subsequent survey of a subset of the images unveiled an additional 106 structures resembling forts, suggesting that there may be even more Roman forts yet to be discovered. The researchers estimate that these forts were constructed between the second and sixth centuries based on excavations of other Roman sites in the region.

The newfound understanding of these Roman forts challenges the notion that they were purely military fortifications. Instead, it suggests that they served as oases of safety and order along the well-traveled Roman roads, facilitating cultural exchange and the movement of goods and ideas.

Casana pointed out the potential lessons from history, stating that ancient attempts to build walls across borders have historically been unsuccessful. Drawing from the perspective of archaeology, he hopes to contribute to the discourse of modern times, emphasizing that building giant walls to keep people out is an ill-advised strategy.

The declassified spy satellite photos not only provide a glimpse into the past but also reshape our understanding of the Roman Empire's eastern border and the role of these forts within it. As further investigations are conducted in the region, more revelations about the impressive Roman infrastructure are expected to come to light.